The present invention relates to an engine shut-down control device for controlling starting and stopping of an automotive engine, and more particularly to a device for prohibiting stopping and/or restarting the engine before the engine stops completely.
Some methods have been formerly proposed in order to stop engines such as diesel engines. One method is to cut the fuel supply by a stop lever or to stop the intake air supply by shutting a valve provided in an intake pipe.
For example, a key switch actuates a solenoid for stopping a fuel injection pump, and which is disclosed in the Japanese utility model publication No.61-167436 (1986) and No. 61-171843 (1986) as a prior art.
According to the prior art disclosed above, the key switch must be kept in electrical contact with the accessory terminal until the engine is stopped. However, returning the switch is easily forgotten, so that the battery is unnecessarily discharged.
In order to eliminate such an inconvenience as described above, there has been proposed a device to stop the engine by using a timer 1 as shown in FIG. 1, and which is disclosed in detail in Japanese patent publication No. 56-1464 (1981).
Namely, the timer 1 starts its operation at the same time as when an engine is stopped and a key switch is turned off. A solenoid controller controls a solenoid to be supplied with electric power from a power source during operation of the timer. Therefore, the solenoid actuates a fuel cut lever to forcibly cut the fuel supply so as to stop the engine.
However, in this prior art, the operational time of the timer must be set to the necessary and longest time in consideration of discrepancies between engines. The timer is constructed so that operation thereof is given priority to be reset so as not to electrify the solenoid when the key switch is turned on erroneously or the condition that the engine does not stop completely while the timer operates. As a result, it is possible to damage the starter by large loads even if the operator starts the starter under the above conditions.
Also, in gasoline engines, the same problem as mentioned above occurs if the operator operates the starter erroneously when the engine does not stop completely during idling or after turning off the key switch.
Furthermore, a conventional diesel engine has the problem of wasting electric power by keeping the solenoid turned on after the engine stops during the operation time of the timer. The operation time is set at the longest time to stop the engine after cutting the fuel supply taking into consideration the difference between engines.